The present invention relates to a new and improved construction of apparatus for the releasable, force-locking or frictional clamping or connection of two tubes which are arranged within one another, in other words telescopic tubes, especially for clamping the steering housing tube in the steering fork tube of a bicycle or the like, there being provided an expanding cone axially displaceable within the inner one of the aforementioned tubes by means of a threaded spindle.
With heretofore known apparatuses of this type the inner end of the inner tube is subdivided by separation cuts into a number of, usually two, flaps or tabs and the outer surface of the expanding cone acts upon the inner end edge of each of these flaps or tabs. During tightening of the threaded spindle these flaps are spread outwardly and only just their outer end edge comes into line-like, force-locking or frictional engagement with the inner jacket surface of the outer tube. Since the play between the outer tube and the inner tube, as a practical manner, cannot be avoided, this results in a force-locking arrestment only along a circular-shaped contact line between the inner tube and the outer tube, which arrestment or locking action is not capable of withstanding any larger forces. A more forceful tightening of the threaded spindle, on the one hand, can lead to a further deformation of the flaps at the end of the inner tube, and, on the other hand, to pitting or so-to-speak "eating away" of the inner jacket surface of the outer tube, without there having been obtained any advantage. This is particularly then disadvantageous when a bending moment acts upon both tubes and at the same time there should be transmitted a torque or rotational moment from the one to the other tube.